I have two tables - one with parent Records, the other with child records. The ID links the two tables together.

I want to add a sequence number on the child table which resets at each ID change. What would be the best way to accomplish this?


PC_ID       ID    Name        Address

P           1     Parent1     Address1        
P           2     Parent2     Address1        





PC_ID       ID    Name        Address         SEQ

C           1     Child1      Address1        1
C           1     Child2      Address1        2
C           1     Child3      Address1        3
C           1     Child3      Address1        4
C           2     Child1      Address1        1
C           2     Child2      Address1        2
C           2     Child3      Address1        3